Explore topic-wise InterviewSolutions in Current Affairs.

Difference between Schottky defect and Frenkel defect:

Ionic compounds have high melting points because there is electrostatic forces of attraction between their charges.

Plant hormones help to coordinate growth, development and responses in environment. Four different types of plant hormones are – Auxins, Gibberellins, Cytokinins, Ethylene and Abscisic acid.

• Auxins control the tropic (growth related) movements of the plants in response to light, gravity, touch etc by increasing the size of cells. Under the influence of auxins, the plant stem bends towards unidirectional light where as the roots bend away from it. Gibberellins stimulate stem elongation and leaf expansion. Its application causes stem elongation in small plants such as cabbage. Spraying gibberellins on sugarcane plant increases the stem size and hence the yield. 
•  Cytokinins are produced in regions of the plant body where rapid cell division occur, such as root tips, developing shoot buds, young fruits and seeds. Cytokinins promote growth by stimulating cell division. They also help in production of new leaves and chloroplasts in leaves. 
• Ethylene causes ripening of the fruits. 
• Abscisic acid inhibits (i.e., slows down) the growth in different parts of the plant body. It also inhibits germination of seeds. It increases the tolerance of plant to different kinds of stresses such as temperature changes. So, it is also called the stress hormone in plants. It also causes the drying and falling of older leaves, flowers and fruits.

The chemical compounds released by stimulated cells for control and coordination in plants are called plant hormones or phytohormones.

Auxin - controls growth

Gibberellins - helps growth in stem

Cytokinin-promotes cell division

Abscisic acid- Inhibits growth, wilting of leaves

(i) Ionic compounds have high melting and boiling points due to strong force of attraction between oppositely charged ions. 

(ii) It is because these metals themselves are strong reducing agents. Therefore, cannot be reduced by reducing agent like carbon. 

(iii) Copper vessels react with CO₂,O₂ and moisture to form green-coloured basic copper carbonate

[CuCO₃.Cu(OH)₂].

(i) Dwarfism

(ii) Tallness

(iii) Diabetes

(iv) Goitre

Correct answer is (b) progesterone

1. With the advent of TV, internet and other audio visual forms of entertainment, people started believing that radio will bean outdated form of mass communication but this thinking proved wrong. 

2. In 2000, AIR’s programmes could be heard in two-third of Indian household in 24 languages and 146 dialects, over some 120 million radio sets. The advent of privately owned FM radio stations in 2002 provided a boost to entertainment over radio. – 

3. In order to attract audiences, these privately run radio stations sought to provide entertainment to its listeners. 

4. As privately rim FM channels are not permitted to broadcast any political news bulletins, many of these channels specialize in ‘particular kinds’ of popular music to retain their audiences. One such FM channel claims that it broadcasts ‘All hits all day’. 

5. Most FM channels which are popular among young urban professional and students often belong to media conglomerates. Like ‘Radio Mirchi’ belongs to the Times of India group, Red FM is owned by Living Media and Radio City by the Star Network. But independent radio stations engaged in public broadcasting like National Public Radio (USA) or BBC (UK) are missing from our broadcasting landscape.

 6. The use of radio m movies—In the two films ‘Rang de Basanti’ and ‘Lage Raho Munna Bhai’ the radio is used as an active medium of communication although both the movies are set in the contemporary period. In ‘Rang de Basanti’ die conscientious, angry college youth, inspired by the Legend of Bhagat Singh assassinates a minister and then captures All India Radio to reach out to die people and disseminate their message. 

7. The potential for using FM channels is enormous. Further privatization of radio stations and the emergence of community owned radio stations would lead to the growth of radio stations. The demand for local news is growing. The number of homes listening to FM in India has also reinforced the worldwide trend of networks getting replaced by local radio.

(a) Almost similar to epinephrine

Correct answer is (c) adrenal

Correct answer is (b) A-iv, B-i, C-iii, D-ii

(a) Figure

(ii)

(b) Geotropism.

Abscisic acid is called stress hormones as it induces various responses in plants against stress condition. It induces the closure of the stomata during water stress. It promotes seed dormancy and ensures seed germination during favourable conditions.

(a) Sensory, motor and mixed nerves 

(b) Somatic and autonomic nervous system 

(c) Natural and conditioned reflexes 

(d) Sensory, motor and association neurons 

(e) Gray and white matter

(a) Abscisic Acid

(b) Cytokinin

(c) Auxin

(d) Abscisic Acid

Correct answer is (c) melatonin

a) Oestrogen hormone is responsible for the changes noticed in females at puberty

b) Dwarfism results due to deficiency of Growth Hormones. 

c) Blood sugar level rises due to deficiency of Insulin Hormone 

d) Iodine is necessary for the synthesis of Thyroxine Hormone

(a) Stimulus --- receptor --- sensory neuron --- central nervous system --- motor neuron --- effector --- response 

(b) Resting --- depolarization --- repolarization

(c) Dendrites --- Dendron --- perikaryon --- nucleus --- axon --- axon endings 

(d) Cerebrum --- diencephalon --- mid-brain --- cerebellum --- pons --- medulla oblongata

Given statement is true.

Explanation- Abscisic acid with their secretion prevents the further growth of plant and thus inhibits it. Therefore, given statements is true.

Roots grow downwards, towards gravity while shoot usually grow upwards and away from earth.

The answer is (b) chemotropism

Chemicals released by ovules stimulate the growth of pollen tubes towards ovules.

Shoots of a plant always grow upwards i.e. they grow away from the earth whereas the roots of a plant grow downwards in the earth i.e. they grow towards the earth.

Abscisic acid is responsible for the wilting and falling of leaves in plants.

The scientist, Ivan Pavlov conducted experiment on a dog to show conditioned reflex.

The advantages of having a nervous system are as follows: 

(a) Keeps us informed about the outside world through sense organs. 

(b) Enables us to remember, think and reason out. 

(c) Controls and harmonizes all voluntary muscular activities such as running, holding, writing 

(d) Regulates involuntary activities such as breathing, beating of the heart without our thinking about them.

“Many people simply see The world in black and white But through my eyes the world’s alive So colourful and bright Don’t close your mind to the sights That light up the night and day There’s so much to see here on this earth And not a rupee do you have to pay” The most obvious things aren’t the ones There is beauty in the unknown with willing eyes and an open mind The true wonders you will be shown

Cell body, dendrites and axon.

(i) Simple reflex.

(ii) Conditioned and modified reflex.

(iii) Conditioned reflex depending upon reasoning and past experience.

(iv) Simple reflex.

(v) Simple reflex.

(a) Dendrites.

(b) Axon.

(a) False 

Correct statement: Deafness is caused due to rupturing of the eardrum.

(b) False 

Correct statement: Semicircular canals are concerned with dynamic balance.

Yellow spot has more cones and less rod cells. Blind spot has no photosensitive cells.

(a) True

(b) False/ Ciliary muscles regulate the size of the lens.

(c) True

(d) False/The auditory nerve responsible for sound as well as for the body balance.

(e) True

(f) False/ flavour is a combination of taste and smell.

(g) False/ short-sightedness is myopia and hyperopia is long-sightedness.

(h) True

Lachrymal gland is a secretary gland present in top right part of the eye. Its secretion is called tears which lubricates the eye and is antiseptic in nature.

Cerebrum is most important part of the human brain .

(a) Lacrimal gland is a tear gland located at the upper sideward portion of the eye orbit. Its secreation lubricates the surface of the eye, washes always the dust particles and kills germs

(b) Yellow spot is the region of brightest vision and contains maximum sensory cells whereas a blind spot contains no sensory cells and this is the point of no vision.

(c) Presbyopia is an age-old eye defect. In this condition, the lens loses flexibility resulting in far-sightedness. Cataract is also very common in old people, the cornea becomes opaque and the vision is cut down even to blindness.

(d) The process of focusing the eye at different distances is called the power of accommodation.

(e) The image formed on the retina is inverted and real.

The ability of the lens by which the light ray from far and near objects is focused on the retina is called accommodation power of the lens. The lens makes fine adjustments to bring such sharp focus on retina

(a) Auditory canal, tympanum, ear ossicles, oval window, cochlea 

(b) Conjunctiva, cornea, lens, retina, optic nerve

Function: 

(a) Cerebellum ? It helps in maintaining posture and balance of the body. 

(b) Pons ? It regulates the respiration process.

Pituitary is located inside a depression called sella turcica which is present in sphenoid bone of the skull.

(a) Organ of Corti and hearing 

(b) Olfactory nerve and smell 

(c) Retina and vision 

(d) Taste bud and taste

Lorain dwarf is mentally normal while Frohlic dwarf is mentally abnormal.

The hormones that control and coordinate the activities in plants are called plant hormones. 

The four types of plant hormones are: 

(i)  Auxins – It promotes cell enlargement and cell differentiation in plants. 

(ii) Gibberellines – It helps in breaking the dormancy in seeds and buds. 

(iii) Cytokinins – It promotes cell division in plants. 

(iv) Abscisic acid – It promotes the dormancy in seeds and buds.

(i) Movement on the touch-sensitive plant.

(a) Synapse: It is a gap between the axon terminal of one neuron and the dendrites of the adjacent neuron. It transmits nerve impulse from one neuron to another neuron.

(b) Association Neuron: It interconnects sensory and motor neurons.

(c) Medullary sheath: It provides insulation and prevents mixing of impulses in the adjacent axons.

(d) Medulla Oblongata: It controls activities of internal organs such as peristalsis, breathing and many other involuntary actions.

(e) Cerebellum: It maintains balance of the body and coordinates muscular activity.

(f) Cerebrospinal Fluid: It acts like a cushion and protects the brain from shocks.

(a) Cerebellum maintains balance of the body and coordinates muscular activity. 

(b) Myelin sheath acts like an insulation and prevents mixing of impulses in the adjacent axons.

Simmond’s disease is caused due to hyposecretion of GH during adulthood.

The stimulation from the nerve cells of the receptor organ passes into the spinal nerve (along the dorsal root) into the spinal cord and from there it goes straight to the brain. From the brain another impulse passes, to the spinal cord and travels along the ventral root of the spinal nerve to reach the effector organ (a muscle), the activity of which is a response to the nerve impulse which has come from the brain.

Shoots will bend towards the light and roots away from the light.

Thyroxine hormone regulates the carbohydrate, protein and fat metabolism in the body so as to provide the best growth balance.